TY - JOUR
T1 - Pneumococcal carriage and disease in adults in England 2011-2019: the importance of adults as a reservoir for pneumococcus in communities
AU - Safadi, Dima El
AU - Hitchins, Lisa
AU - Howard, Ashleigh
AU - Aley, Parvinder
AU - Bowman, Jaclyn
AU - Bertran, Marta
AU - Collins, Andrea
AU - Colin-Jones, Rachel
AU - Elterish, Filora
AU - Fry, Norman K.
AU - Gordon, Stephen
AU - Gould, Kate
AU - Hinds, Jason
AU - Horn, Emilie
AU - Hyder-Wright, Angela
AU - Kandasamy, Rama
AU - Ladhani, Shamez
AU - Litt, David
AU - Mitsi, Elena
AU - Murphy-Fegan, Annabel
AU - Pollard, Andrew J.
AU - Plested, Emma
AU - Pojar, Sherin
AU - Ratcliffe, Helen
AU - Robertson, Maria C.
AU - Robinson, Hannah
AU - Snape, Matthew D.
AU - Solórzano, Carla
AU - Voysey, Merryn
AU - Begier, Elizabeth
AU - Catusse, Julie
AU - Lahuerta, Maria
AU - Theilacker, Christian
AU - Gessner, Bradford D.
AU - Tiley, Karen S.
AU - Ferreira, Daniela
PY - 2025/1/15
Y1 - 2025/1/15
N2 - Background Pneumococcal carriage in children has been extensively studied, but carriage in healthy adults and its relationship to invasive pneumococcal disease (IPD) is less understood. Methods Nasal wash samples from adults without close contact with young children (Liverpool, UK), 2011-2019, were cultured, and culture-negative samples tested by PCR. Pneumococcal carriage in adults 18-44 years was compared with carriage among PCV-vaccinated children 13-48 months (nasopharyngeal swabs, Thames Valley, UK) and IPD data for England for the same ages for 2014-2019. Age-group specific serotype invasiveness was calculated and used with national IPD data to estimate carriage serotype distributions for adults aged 65+ years. Results In total 98 isolates (97 carriers) were identified from 1,631 adults aged 18+ years (age and sex standardized carriage prevalence 6.4%), with only three identified solely by PCR. Despite different carriage and IPD serotype distributions between adults and children, serotype invasiveness was highly correlated (R=0.9). Serotypes 3, 37 and 8 represented a higher proportion of adult carriage than expected from direct low-level transmission from children to adults. The predicted carriage serotype distributions for 65+ years aligned more closely with the carriage serotype distribution for young adults than young children. Conclusions The nasal wash technique is highly sensitive; additional benefit of PCR is limited. Comparison of carriage serotype distributions suggests some serotypes may be circulating preferentially within these specific young adults. Our data suggest that for some serotypes carried by adults 65+ years, other adults may be an important reservoir for transmission. Age groups such as older children should also be considered.
AB - Background Pneumococcal carriage in children has been extensively studied, but carriage in healthy adults and its relationship to invasive pneumococcal disease (IPD) is less understood. Methods Nasal wash samples from adults without close contact with young children (Liverpool, UK), 2011-2019, were cultured, and culture-negative samples tested by PCR. Pneumococcal carriage in adults 18-44 years was compared with carriage among PCV-vaccinated children 13-48 months (nasopharyngeal swabs, Thames Valley, UK) and IPD data for England for the same ages for 2014-2019. Age-group specific serotype invasiveness was calculated and used with national IPD data to estimate carriage serotype distributions for adults aged 65+ years. Results In total 98 isolates (97 carriers) were identified from 1,631 adults aged 18+ years (age and sex standardized carriage prevalence 6.4%), with only three identified solely by PCR. Despite different carriage and IPD serotype distributions between adults and children, serotype invasiveness was highly correlated (R=0.9). Serotypes 3, 37 and 8 represented a higher proportion of adult carriage than expected from direct low-level transmission from children to adults. The predicted carriage serotype distributions for 65+ years aligned more closely with the carriage serotype distribution for young adults than young children. Conclusions The nasal wash technique is highly sensitive; additional benefit of PCR is limited. Comparison of carriage serotype distributions suggests some serotypes may be circulating preferentially within these specific young adults. Our data suggest that for some serotypes carried by adults 65+ years, other adults may be an important reservoir for transmission. Age groups such as older children should also be considered.
KW - adults
KW - carriage
KW - invasive pneumococcal disease
KW - pneumococcal
KW - transmission
U2 - 10.1093/infdis/jiae351
DO - 10.1093/infdis/jiae351
M3 - Article
SN - 0022-1899
VL - 231
SP - e17-e27
JO - Journal of Infectious Diseases
JF - Journal of Infectious Diseases
IS - 1
ER -
